First you need to do a port fowarding go to cmd type in ipconfig then where it says default getaway
get that ip and type it on the url bar . Then you need to look for ur account on the wirless modem or internet modem
type in the pass and name then go to Advence then to Port Forwarding type in the name ip addreas public port then if you want to check that u dont the Port Forwarding download the program called PFPortChecker then check and if its done then go back to Advence and this time go to Firewall & DMZ DMZ means "Demilitarized Zone". DMZ allows computers behind the router firewall to be accessible to Internet traffic. Typically, your DMZ would contain Web servers, FTP servers and others.
Enable the dmz time the ip addreas in . Then selecte you're computer name save it and it should be working .
Hope it will work .